Extraction of bitumen from mined oil sands ore has been practiced in Alberta, Canada, for many years. Bitumen extraction processes can be water-based processes, solvent-based processes or a combination of water-based and solvent-based processes. In water-based bitumen extraction processes, generally, the mined oil sands ore is crushed and mixed with heated water, steam, and caustic (NaOH) to produce an oil sands slurry that is hydro-transported in a pipeline to a primary separation station. During hydro-transport, turbulent flow of the slurry in the pipeline causes bitumen films surrounding the sand particles to begin to separate, attach to entrained air bubbles, and form bitumen droplets. The primary separation station may comprise a primary separation vessel (PSV) wherein the oil sands slurry is introduced to float the bitumen to the top of the PSV as a bitumen-rich froth, which is generally referred to as “primary bitumen froth”, while middlings remain suspended in the PSV, and an underflow settles to the bottom of the PSV. The middlings, underflow and tailings from the PSV may then be subjected to secondary flotation treatment to recover residual bitumen contained therein (generally referred to as “secondary bitumen froth”). The primary bitumen froth, secondary bitumen froth or both is further treated with a diluent, such as naphtha or paraffin, and subjected to gravitational or centrifugal separation to separate diluted bitumen from tailings.
Oil sands that are processed by bitumen extraction processes are highly variable in their physical properties. Variations in the physical properties of the oil sands feed stock and the various oil sands slurries derived therefrom will affect the mechanical and chemical separation phenomena in the bitumen extraction or tailings reclamation processes. When designing and optimizing bitumen extraction and/or tailings reclamation processes, it can therefore be difficult to ascertain whether a change in process performance is caused by a deliberate change to the process or to chance variation in the slurry/tailings processed by the process. Accordingly, analyzing the slurries, including tailings, to determine their physical properties can yield information that is valuable to predicting and optimizing bitumen extraction and tailings treatment processes, and diagnosing problems in such processes. However, the complicated and heterogeneous nature of oil sands extraction slurries presents unique practical obstacles for conventional analysis equipment. For example, sand grains and solid fines suspended in the oil sands extraction slurries will tend to erode sensing elements placed directly in a slurry flow path. Further still, bitumen in oil sands extraction slurries tend to coalesce and interfere with the proper operation of sensing equipment. While these challenges can be addressed to an extent by using a sampling device to remove discrete samples of oil sands extraction slurries from a slurry transport line, repeated operation of a sampling device may wear and cause failure of seals associated with the sampling device.
Accordingly, there is a need in the art for systems and methods of analyzing slurries such as oil sands extraction slurries. Preferably, such systems and methods address the unique challenges posed by slurries such as oil sands extraction slurries, permit continuous sampling of slurries from a slurry transport line, rapidly analyze the slurries for real-time control and monitoring of bitumen extraction and tailings treatment processes, and provide a tool that can be used for optimization of slurry process performance.